Field of the Various Embodiments
Embodiments of the present disclosure relate generally to personal aural devices and, more specifically, to an acoustic presence detector.
Description of the Related Art
Presence detection sensors are oftentimes deployed in various settings or locations, such as private residences, private businesses, and public spaces, to detect the presence of persons in those settings or locations. One common application of presence detection sensors is to detect the presence of intruders or trespassers. In such an application, when the presence detection sensor detects an intruder or trespasser, a signal is typically transmitted to a security system that, in turn, triggers an audible or silent alarm. Another common application of presence detection sensors is in smart home systems, where the presence of a person in a room triggers one or more actions, such as adjusting the lighting, playing music, or opening or closing a set of curtains.
Various types of presence detection sensors currently exist. Infrared (IR) sensors detect changes in infrared energy, typically by sensing thermal energy or via photosensors that are tuned to the infrared frequency range. Motion sensors detect moving objects, typically by sensing changes in an optical or microwave energy field proximate to the motion sensor. Sensor systems based on image processing approaches capture images via a video camera and apply one or more computer vision techniques, such as edge detection or feature matching, to detect the presence of a person. Laser-based systems include one or more laser sources, where each laser source is paired with a different detector. Each of the detectors is configured to transmit a signal when the laser source corresponding to the detector is no longer sensed, such as when the laser beam generated by the laser source has been interrupted by a moving object or person that crosses the path of the laser beam.
One drawback of existing presence detection sensors is that accuracy decreases as a function of distance from the sensor. Therefore, a presence detection sensor may be unable to detect the presence of a person who is beyond a threshold distance from the sensor. Another drawback is that most types of presence detection sensors have “blind spots,” where the sensor is unable to detect the presence of a person who is outside of an arc defined by a range of angles relative to the sensor. Similarly, some existing presence detection sensors are unable to detect presence of a person who is behind another object in the room, such as a piece of furniture.
One possible solution to these potential problems is to deploy multiple sensors at different locations in a room. Distributing multiple sensors throughout the room increases the number of areas in the room that are in the proximity of at least one sensor. In addition, certain sensors may be placed in a position to cover certain areas in the room that are not detectable by sensors placed in other areas, thereby reducing the number and size of blind spots. One drawback with these possible solutions is that, even with multiple sensors, total coverage of the room and elimination of blind spots is often difficult, if not impossible. Another drawback with these possible solutions is that increasing the quantity of sensors in a room increases costs, particularly with expensive sensor technologies, such as image processing based systems and laser systems.
As the foregoing illustrates, more effective ways to detect the presence of a person in a setting or location would be useful.